U.S. patent number 4,387,992 [Application Number 06/266,137] was granted by the patent office on 1983-06-14 for rotatable cuvette array.
Invention is credited to Peter J. Swartz.
United States Patent |
4,387,992 |
Swartz |
June 14, 1983 |
Rotatable cuvette array
Abstract
A cuvette array comprised of a boat-carrying planar disk with a
plurality of boat members affixed to the disk in an annular array
on one side of the disk, each boat member having a reagent supply
section and a sample section, the disk having a first annular array
of cuvette position identifying means and a second annular array of
reagent/sample access apertures and instrument-transparent sections
of the disk coinciding with portions of the cuvette sections of the
boats affixed thereto.
Inventors: |
Swartz; Peter J. (Randolph,
MA) |
Family
ID: |
23013328 |
Appl.
No.: |
06/266,137 |
Filed: |
May 22, 1981 |
Current U.S.
Class: |
356/246; 356/427;
422/72 |
Current CPC
Class: |
G01N
21/07 (20130101) |
Current International
Class: |
G01N
21/07 (20060101); G01N 21/03 (20060101); G01N
021/07 () |
Field of
Search: |
;356/246,427
;422/72 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
4226531 |
October 1980 |
Tiffany et al. |
|
Primary Examiner: McGraw; Vincent P.
Attorney, Agent or Firm: Nitkin; William
Claims
I claim:
1. An improved cuvette array comprising:
a. means defining a rigid planar member component thereof with
upper and lower faces and a center of rotation having defined
therein analyzer readable indicator means in a circular array about
said center of rotation and further having defined therein
substantially along radial lines with reference to said center of
rotation a plurality of substantially radially elongated
reagent/sample access apertures arrayed in a circular fashion with
their long axes defined on said radii of the planar member and
further having, concentric and outward of the reagent/sample access
apertures, a plurality of first analyzer-readable windows defined
in said planar member, each associated with one of said
reagent/sample access apertures and located respectively on the
same radii of said reagent/sample access apertures' axes;
b. means defining as further components of the cuvette array a
plurality of boat members, each having elongated opposing side
walls, an outer end wall and an inner end wall joined to said side
walls, all said walls having upper rims joined in a fluid-tight
fashion to said planar disk, and a base having integrally formed
therein an in said adjoining side walls a divider of ramp form
defining with said walls and base a reagent chamber on a radially
inner side thereof and a sample chamber on the radially outer side
thereof, each boat member located beneath a reagent/sample access
aperture having its reagent chamber directly below said
reagent/sample access aperture and its sample chamber accessible
through said reagent/sample aperture and below said first clear
optical window, each of said boats having a a clear section in its
base below its respective optical window;
c. the said planar member and boat components being constructed and
arranged for weldability at the upper walls of the rim of each boat
to the planar member; and
d. the thickness of each of the planar members to boat walls being
in ratio between 1:2 to 2:1 and each of the planar members and
walls being within 0.020 to 0.070 inch average thickness.
2. The cuvette array of claim 1 wherein said positioning of said
plurality of boat members under said reagent/sample access
apertures is such that the reagent/sample access apertures are
predominantly over said reagent chambers and only a portion of the
access apertures extends over said ramps and said sample chambers
which is sufficient for the insertion of a pipette into said sample
chambers, i.e. substantially pipette-sized portion) and wherein
said reagent/sample access apertures are narrower than the
separation of said boats' side walls to help to prevent spillage of
reagent from out of said boats when the cuvette array is in
use.
3. The cuvette array of either of claims 1 or 2 wherein the
radially innermost portions of each boat's side walls converge
towards each other to define a tapering of the boat's radially
innermost portion limiting the amount of reagent storable in the
reagent portion of such boat and allowing a higher number of boats
to be clustered annularly and extend inwardly towards said center
of rotation to an extent consistent with high stiffness of the
assembly as a whole through such placement, number and wall
thickness of the boats.
4. The cuvette array of claim 3 wherein said first optical windows
are thinner than the thickness of said planar members.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The device of this invention relates in general to rotatable disk
cuvette arrays and more particularly to an improved and simplified
cuvette array for use in centrifugal chemical analyzer and other
instruments and machines.
2. History of the Prior Art
Rotatable cuvette arrays are well-known in the prior art and are
utilized in many analyzing devices. An extensive discussion of the
prior art is found in U.S. Pat. No. 4,123,173 to Bullock et al.
Other pertinent disclosures of cuvette arrays are found in the
following U.S. Pat. Nos.: 3,679,130 to Mayo et al 3,890,101 to
Tiffany et al 3,759,666 to Hill 3,986,534 to Schmidt 3,532,470 to
Rochte 3,829,223 to Hamel 3,856,470 to Cullis 3,441,838 to Moore
3,873,217 to Anderson et al 3,811,780 to Liston
SUMMARY OF THE INVENTION
It is an object of this invention to produce cuvette arrays
predominantly by an injection molding process and to provide a
product feasibly made by such process. This process produces a more
rigid unit and may ultimately make the cost of the cuvette array
much less than the cost of those produced by other methods of
manufacture.
These objects are met, in accordance with the present invention, by
an improved cuvette array comprising means defining a rigid planar
member component thereof with upper and lower faces and a center of
rotation having defined therein analyzer readable indicator means
in a circular array about the center of rotation and further having
defined therein substantially along radial lines with reference to
the center of rotation a plurality of substantially radially
elongated reagent/sample access apertures arrayed in a circular
fashion with their axes defined on the radii of the planar member
and further having concentric to and outward of the reagent/sample
access apertures, a plurality of first analyzer-readable windows
defined in the planar member, each associated with one of the
reagent/sample access apertures and located respectively on the
same radii of the reagent/sample access apertures axes; and means
defining as further components of the cuvette array a plurality of
boat members, each having elongated opposing side walls, an outer
end wall and an inner end wall joined to the side walls, all the
walls having upper rims joined in a fluid-tight fashion to the
planar disk, and a base having integrally formed therein and in the
adjoining side walls a divider of ramp form defining with the walls
and base a reagent chamber on a radially inner side thereof and a
sample chamber on the radially outer side thereof, each boat member
located beneath a reagent/sample access aperture having its reagent
chamber directly below said reagent/sample access aperture and its
sample chamber accessible through the reagent/sample aperture and
below the first clear optical window, each boat having a clear
section in its base below its respective optical window, the planar
member and boat components being constructed and arranged for
weldability at a closed figure at the upper walls of the rim of
each boat to the planar member; and the thickness of each of the
planar members to boat walls being in ratio between 1:2 to 2:1 and
each member and walls being within 0.020 to 0.070 inch average
thickness.
In order to effectively provide such an assembly, the disk and
boats should be made of the same or weld-compatible plastic
materials of similar thickness. Each should have an average wall
thickness of 0.020-0.070 inch and be in a thickness ratio between
1:2, 2:1 (disk thickness; boat wall) with respect to each other.
While the boat base should preferably fall in the same thickness
range as the boat walls, considerably more leeway can be afforded
to the base.
The boat walls should terminate in upper rims of generally flat,
but having a bead therof, form which can be pressed and vibrated
ultrasonically in contact with the disk to form leak-tight durable
welds over a continuous closed figure boat-disk interface without
cracking any boat portion or the disk region around the access
aperture confronting the boat. In some embodiments though the
closed figure welding may be unnecessary as the leak-tight seal may
only be formed around the upper rim of the outer end of the boat
where the reagent/sample mixture is thrown while the disk is
spinning.
Locating means are provided to rapidly align the boats with and in
proper relation to confronting apertures prior to welding.
Ultrasonic welding is carried out at high speed.
Further objects of the present invention include provision of a
simplified cuvette array that can be reused if desired,
availability to use less reagent than cuvette arrays of the prior
art, and/or other objects apparent from the following disclosure,
singly or in combination.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a top view of the cuvette array of a preferred
embodiment of this invention.
FIG. 2 illustrates a bottom view of the cuvette array of a
preferred embodiment of this invention.
FIG. 3 illustrates a sector-shaped section of the cuvette array in
cutaway view showing the interior of a boat member component
thereof.
FIG. 4 illustrates ulltrasonic welding machine preferably, and with
distinct advantage, used in the method of manufacture of FIGS. 1-3
devices or the like in accordance with a preferred embodiment of
the process of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
FIG. 1 illustrates a top view of the preferred embodiment of this
invention which is comprised of a circular planar member 10 disk
which is injection molded of a polystyrene material having a
thickness of approximately 0.050 inch. Arrayed on its upper surface
in circular configuration are a plurality, and in this illustrated
preferred embodiment, a series of 20 reagent/sample access
apertures 14 which are elongated rectangular (preferably not
elliptical) openings with rounded ends aligned with their long axes
on radii of the circular planar member. Reagents and samples are
inserted by pipettes through the apertures into the reagent (outer)
and sample (inner) sections of the boats which can be mounted on
the disk in alignment with the apertures to form a complete
assembly which process and assembly will be described in further
detail below. Arrayed in an outer circle of the disk are a series
of as-molded first optical windows 16, each associated with one of
said reagent/sample access apertures 14 on its radii. These windows
are clear portions defined within the substantially opague material
of planar member 10. Windows 16 allow a centrifugal chemical
analyzer in which the disk is loaded in per se conventional fashion
of the art to read the reaction. A series of reference notches 12
are arrayed around the perimeter of planar member 10, the rim being
composed of clear plastic. The notches help to identify the
position of the cuvettes so that they can be read by the analyzer.
A series of locating pins are provided to assist in the positioning
of an annular component over the array which component many of the
prior art analyzing devices utilize to assist in aligning the array
within the analyzer.
FIG. 2 is a bottom view showing planar member 10 with a series of
boat members 35 arrayed around the bottom thereof. Each boat member
has elongated side walls 21 and 23 with an inner end 25, outer end
27, and a base 29 with ramp 22 formed integrally as a part of the
base and side walls separating an inner reagent supply chamber
section 26 from an outer sample (cuvette) chamber section 24. Each
injection molded boat member has walls approximately 0.042 inch
thick and is ultrasonically welded as described below to the planar
disk beneath a reagent/sample access aperture with its sample
chamber beneath said first optical window. When inserting the
reagent through the reagent/sample access aperture by pipette, one
inserts the reagent into the reagent chamber and the sample into
the sample chamber. An optically clear section 20 is located in the
base of each boat member 35 in vertically opposing position to the
first optical window 16 of planar member 10 so that the analyzer
can detect the contents therethrough of the sample chamber aligned
therewith. In one embodiment the entire base may be optically
clear. The shape of at least the inner third (radially) of each
boat tapers toward the center of the disk so that each boat may be
properly positioned in a circular array without contacting one
another. The boat members, or at least the reagent supply sections
thereof, are also constructed in such a narrow configuration
overall so that they are adapted to hold in the range of 350
microliters to 1 milliliter.
It is desirable to maintain such narrow configuration so that the
volume of reagent used for analysis is kept small consistent with
reliable analysis. Ramp 22 must not reach all the way up to contact
planar member 10 because when the cuvette array is spun, the
reagent, by centrifugal force, must travel over the ramp and mix
with the sample in the sample chamber. It is important that the
reagent access aperture be just large enough to allow the pipettes
delivering the samples and reagents into their respective chambers
but narrow and short enough to prevent fluid from splashing back
out therethrough when the device is in use. An aperture
approximately 1 inch in length and approximately 3/16 inch in width
with its outer end extending beyond ramp 22 approximately 1/16 inch
has been found to work well in conventional centrifugal analyzers
of today's art at speeds of 100 rpm to 500 rpm and
acceleration/deceleration and vibration and rigidity of mounting
conditions currently prevalent.
FIG. 3 shows a cutaway view of a section of single boat member 35
showing ramp 22 over which the reagent must flow when the array is
spun in the analyzer causing it to mix with the sample within the
sample chamber and then be read by the analyzing device.
FIG. 4 illustrates an ultrasonic welding machine 100 showing a boat
nest fixture 102 with boats 104 in place therein and with disk 106
shown suspended thereabove. The injection molding of all twenty-one
parts of the disk helps to produce a rigid product. In the
injection molding process the first clear optical windows are all
depressed on their upper and lower surfaces 0.002 inch from the
face of the disk so that they will not be scratched during the
assembly process. Each boat is molded having a bead 40 on its upper
edges of its open side so that when placed into nest 102, which
exactly positions each boat, the disk can be accurately positioned
and referenced and ultrasonically welded to the boats in one
operation by the ultrasonic welding machine 100, which machines are
well-known.
Although the present invention has been described with reference to
particular embodiments, it will be apparent to those skilled in the
art that variations and modifications can be substituted therefor
without departing from the principles and spirit of the
invention.
* * * * *